How to Solve “Could not open lock file /var/lib/dpkg/lock-frontend” Error

While using Linux, you may encounter various errors. One of them could be “/var/lib/dpkg/lock” error. Is it fixable? Well, yes!  It is not a panicky error. But before we learn how to fix this error, let’s understand why this error occurs.

Why “/var/lib/dpkg/lock” Error Occurs

This error usually occurs when a process is functioning to update the system, and you try to access the system for some other operation. For example, the Ubuntu system locks the “dpkg” access to prevent the operating system from failing the update process. It may also occur due to an arbitrary process that is continuously running in the background and keeping the “/var/lib/dpkg” engaged.

These processes prevent you from installing new applications or execute a command. There are multiple methods to solve this issue. First, carefully diagnose the problems and then go for the fix. Let’s understand how to fix this issue.

Strategies to Solve “/var/lib/dpkg/” Error

As discussed above, before going for the fix, first make sure everything in the system is perfect. Next, ensure that no application is being installed or updating the system; if yes, then wait for the application to finish the installation.  After that, the issues will automatically be resolved.

If there is no apparent problem and you are still getting this error, then check the process that is using package manager by typing the command below:

$ ps aux | grep -i apt

In my case, Ubuntu is being updated. During this process, “dpkg” is locked, and I can’t perform some other task as demonstrated in the following image.

The fix is simply to let the update finish. If this is not helpful, then this issue can also be fixed by killing the process that has kept the “dpkg” engaged. Firstly, identify the process. In many cases, the process id is mentioned in the error message or you can get a list of processes using “apt” by the below-mentioned command:

$ ps aux | grep -i apt

Now, to terminate the process, use:

$ sudo kill [Process ID]

If it does not solve the issue, kill the process forcefully using SIGKILL signal:

$ sudo kill -9 [Process ID]

The simplest way is to kill all the processes occupying “apt” and “apt-get” as mentioned below:

$ sudo killall apt apt-get

How to Fix “/var/lib/dpkg/lock-frontend” Error

You may come across a more complex situation, and the issue could be the “lock” files. Lock files restrict access to the system files until a specific operation is performed. Upon completion of the process, the lock will automatically be released to perform further operations of the system. So, to solve this issue, you are required to delete the lock files. Firstly, check the lock file using:

$ sudo lsof /var/lib/dpkg/lock-frontend

If you see something “unattended” in the output, wait for this process to complete because the system is working on updates.

Otherwise, get the process ids and terminate them using:

$ sudo kill -9 [Process ID]

After that, you can delete the lock file:

$ sudo rm /var/lib/dpkg/lock-frontend

Make sure you reconfigure the “dpkg” after deleting the lock file:

$ sudo dpkg --configure -a

To ensure everything is normal and error has been fixed, run:

$ sudo apt update


Various “/var/lib/dpkg” errors usually occur when the system restricts the user from performing an operation because other key processes utilize the system files. In this write-up, we discussed different strategies to get rid of this error. Moreover, we also learned how to remove “/var/lib/dpkg/lock-frontend” error.

The error occurs because of lock files, and safely removing the lock files can resolve this issue. Although it is not recommended to remove the lock files to avoid any trouble, ensure you use the correct method to erase the lock file.

About the author

Sam U

I am a professional graphics designer with over 6 years of experience. Currently doing research in virtual reality, augmented reality and mixed reality.
I hardly watch movies but love to read tech related books and articles.